Environmental learning in the 21st-century must be contextual and require the ability of Higher-Order Thinking Skills (HOTS) to solve environmental problems such as green consumerism. The purpose of this study was to implement an Android-based Supplementary Book of Green Consumerism (SBGC) to improve 8th-grade students' HOTS in environmental learning. The method used experiment with a sample of 144 students in 8th grade. This research design was a pre-post test with the control group. The treatment given was in the form of using SBGC in the experimental classes. The instrument used 12 items with HOTS questions (analyzing, evaluating, and creating) that contain a green consumerism problem. Analysis of the data used the normality test, homogeneity and continued with the t-test. The results showed that the students HOTS score increased significantly in the pre-test and post-test in the experimental class or compared to the control class. Increased in the experimental classes from a score 15.7 (very low) to 32.73 (low). Meanwhile, comparison between the experimental classes with a score 32.73 (low) and control classes with a score 25.25 (very low). This showed that SBGC is easy to understand and have instruction to solve environmental learning in SBGC menu. SBGC is also interesting so that makes students become active in learning. The conclusion of this study was that SBGC can increased students' HOTS in environmental learning.